Thinking heatmap

The thinking heatmap is a GitHub-style calendar of ideas developed over the last 52 weeks — momentum you actually care about, not a "notes created" volume chart. It rewards developing ideas: advancing a note's state, adding a source, adding a connection.

Opening it

Run "Show thinking heatmap" from the command palette, or click Open next to Thinking heatmap in Settings → ZettelFlow → Zettelkasten toolkit. Each cell is one day, coloured by how many development events happened, and is keyboard-focusable with a descriptive label ("N ideas developed on YYYY-MM-DD").

What counts as "development"

The journal records an event when — comparing a note before and after an edit — one of these happens (creation itself does not count; momentum is about developing existing ideas):

Event	Fires when
State advanced	the note's lifecycle state factor rose (e.g. fleeting → permanent)
Source added	the note gained its first source
Connection added	the note's outgoing links grew

Events are detected at the knowledge-index's upsert choke point by diffing the note's model signals; the initial vault scan is bypassed so first-load never floods the journal.

The journal (local & private)

The data source is a capped, per-day count map stored in the plugin's data.json: { "2026-08-12": 3, … } — day → count only. It records no note names, no content, and makes no network request. It is pruned to the last ~year, and persisted with a debounced save so a burst of edits collapses to one write.

It is on by default (it only records benign aggregate counts); turn it off any time under Settings → ZettelFlow → Thinking journal. See Capabilities & privacy.

Architecture

detectDevelopmentEvents(before, after)   (pure, Obsidian-free, unit-tested)  → event types
buildHeatmapGrid(counts, now, weeks)     (pure, unit-tested)                  → 52×7 cells + levels
recordDay / pruneCounts                  (pure, unit-tested)                  → bounded tally update

DevelopmentJournal (runtime singleton, host injected at load)
  fed at KnowledgeIndex.upsert (best-effort, wrapped so it can never break indexing)
  reads/writes settings.journal.counts, debounced saveSettings

ThinkingHeatmapView (ItemView) + ThinkingHeatmapComponent (command, no hotkey)
  intensity is a --l0…--l4 CSS class (theme-aware), each cell aria-labelled + focusable